Analysis of abnormal genotype of STR loci on sex chromosomes in paternity testing

Objective:To observe the characteristics of the abnormal genotype of STR loci on sex chromosomes,investigate the relationship with sex chromosomegenetic diseases. Methods:In 3200 cases of paternity testings and about 8356 individuals,Chelex100 method was adopted to extract DNA,composite amplification of STR loci on autosomal and sex chromosomes,fluorescence detection.The abnormal genotype of STR loci were examined by sex chromosomeSTR loci, peripheral blood cell chromosome karyotypeanalysis was carried out on the sex chromosomesgenetic diseases diagnosis. Results:In two cases,the peak height rate of X and Y allele was 2:1 in Amelogeningene.Two cases were respectively diagnosed with Turner syndromeand Klinefelter syndrome,by using the STR genotyping and Karyotypeanalysis. Conclusions:Sex chromosomeSTR genotyping has certain application value in screening.of sex chromosomesgenetic disease